Method and means for sampling pulverulent material



May 6, 1969 o. H. STOHLDRIER 3,

METHOD AND MEANS FOR SAMPLING PULVERULENT MATERIAL Fil ed Oct. 20, 1966AIF? ig. 2 IN VENTOR.

OLIVER H. STOHLDRIER AGENT United States Patent Int. Cl. G01n .I/OO US.Cl. 73-422 Claims ABSTRACT OF THE DISCLOSURE A sample of pulverulentmaterial is obtained by passing the pulverulent material between a gasjet and an openended sample collector. Periodically a blast of air isemitted by the gas jet to blow a sample of the material into the samplecollector.

The present invention relates in general to sampling devices and moreespecially to an improved method and means for obtaining samples ofpulverulent materials.

For many purposes it is desirable to obtain samples of pulverulentmaterials flowing in a stream, as for example from one stage of aprocess to another, which samples are fully representative, ascompositions, of the material throughout the stream. Various samplingdevices have been used in the past such as for example the auger-typecontinuous sampler, and a great variety of mechanical devicescharacterized by a sample receiver adapted to be moved periodically intoand out of the stream. Each of these devices has had one seriousdrawback namely, the ever present possibility of contaminating thesample with abraded metallic particles.

Moreover, earlier devices have been limited by mechanical structure andmode of operation to relatively slow sampling cycles with no means forvarying the frequency and duration thereof.

An object therefore of the present invention is to obtain samplesperiodically from a stream of pulverulent material which are fullyrepresentative thereof and which are free of any foreign materials thatmight result from the operation of the sampling device.

A further object of the invention is to provide a pneumatic samplingwhich is of simple, low cost construction and involves no moving parts.

Another object of the invention is to provide a pneumatic samplingdevice wherein samples from a stream of moving pulverulent material maybe takenat variable frequencies and duration.

These and other objects, features and advantages of the invention willbe described in more detail below with reference to the drawings inwhich:

FIG. 1 is a vertical elevation, partly in section, of the pneumaticsampling device of this invention.

FIG. 2 is a fragmentary schematic view of modified air supply means foruse in conjunction with the timer controlled valve-means of FIG. 1.

In general the sampling device of this invention is pneumatic inprinciple in that it involves no moving parts but on the contraryemploys a short blast of air to remove a sample of pulverulent materialfrom a flowing stream of the same. While it is most probable that thestream of pulverulent material to be sampled will be flowirrg downwardlysubstantially vertically, the sampling device of this invention is notlimited in its operation to vertically flowing streams but may be usedwith streams flowing at an angle to the vertical or even horizontally ifsuch be the case.

More particularly the sampling device of this invention is one whichinsures minimum contact with the material 3,442,137 Patented May 6, 1969to be sampled by employing a short blast of high pressure gas i.e., airto other inert gaseous material, to remove the sample from the stream ofpulverulent material being sampled. The short blast of gas is adapted toemanate from one side of the conduit through which the pulverulentmaterial is flowing and to shoot across the stream at substantiallyright angles to its direction of flow. In so doing the blast of gaspicks up a sample of the pulverulent material from the stream andcarries it across to the opposite side of the conduit. Here at a pointdiametrically opposite the gas blast is suitable sample collecting meansthat collects the sample material segregated from the stream by the gasblast.

The present invention is comprehensive of various means for effectingpneumatic sampling of a stream of pulverulent material and one suchmeans which has been used with considerable commercial success, isdescribed in more detail below.

Referring to the drawings the numeral 10' identifies a conduit, in thisinstance arranged substantially vertically, through which flows a streamof pulverulent material to be sampled. The pneumatic means for taking asample from this stream comprises in part, a tubular member 11 adaptedto project through an aperture in the wall 12 of the conduit 10 and tobe rigidly secured therein by welding or equivalent fastening meansindicated by plate 13. The forward end of the tubular member is adaptedto project a slight distance into the conduit and is provided with a jetorifice 14, while the opposite or rear end of the tubular member 11 isconnected by a coupling 15 to the adjoining end of a pipe line 16 whichis an extension of gas supply means 17 to which a gas, i.e. air is fedat superatmospheric pressure from a source not shown. Interposed in thepipe-line 16 between the coupling 15 and the air supply means 17 is avalve-means 18 which in one embodiment of the invention is adapted to beoperated automatically by means of a solenoid or equivalent means. Itwill be understood however that the valve-means 18 may be operatedmanually if so desired. Where the valve-means 18 is operated by asolenoid the latter, as shown in the drawing, is adapted to be connectedin an electrical circuit which includes a timer 19 whereby the frequencywith which the solenoid is energized and the length of time between.intervals may be varied thereby varying the frequency with which samplesare taken and also the duration of each sampling.

Diametrically opposite the tubular member 11 is sample collecting means20. The latter is adapted to collect a sample of the pulverulentmaterial shot into it by the air blast and to carry the sample to apoint outside the conduit 10 where the sample may be subsequentlyanalyzed. One sample collecting means adapted to perform this functionis shown in the drawings as comprising a tubular collector member 20 anda sample receiver 21. The tubular collector 20 is in the shape of a pipeelbow arranged to be rigidly secured in an aperture in the wall 22 ofthe conduit 10 by welding or equivalent fastening means represented byplate 23.

It is essential to truly representative samples that the samplercollects only the samples shot into it by the air blast and that it beshielded, normally, from pulverulent material flowing through theconduit. To this end the collector 20 is so arranged that its entranceend, indicated by numeral 24, projects into the path of the stream ofpulverulent material but is directed downwardly so that in effect it isshielded from the normal flow of pulverulent material through theconduit. The opposite or exit end 25 of the collector member 20 islocated on the outside of the conduit 10 and is adapted to dischargesamples into the sample receiver 21 for subsequent analysis. In itssimplest form the sample receiver may comprise a cupshaped member but itwill be appreciated-that the latter may be one of a plurality of suchreceptacles adapted to be automatically positioned beneath the exit endof the sample collector for receiving successive samples therefrom.Since in commercial applications the sampler will be located almostinvariably in an area that is prone to be dusty it is important that thesample receiving receptacle or cup 21 make a dust-tight fit with theexit end 25 of the collector 20 and to this end the latter may beprovided with a gasket 26 to seal off the upper end of the cup.

Concerning the frequency and duration of the sampling cycle-in oneparticular application of the sampler only a very small quantity ofsample material was desired and it was found that most commercial timershaving the desired cyclic frequency had an on-interval which was muchtoo long to obtain small samples. Hence a modified airsupply means wasdevised which, as shown in F162, comprised an air chamber 27 provided atits air inlet end with a restricter 28. The opposite end 29 of the airchamber was connected to the air supply line 17. With this arrangementthe flow of air to the supply line 17 was restricted with the resultthat once the timer controlled solenoid has been actuated to open thevalve to emit a short blast of air, thereafter the restricter 28 bledair into the air supply line 17 so slowly that even though the solenoidoperated valve remained open (because of the long on-interval of thetimer) there was not sufficient air pressure to blast a sample from thestream of material being sampled. At the end of the on-interval of thetimer the solenoid was actuated to close the valve and air pressure thenbuilt up in the supply line 17 suflflciently to blast a sample from theStream when the valve was again opened.

The pulverulent materials that may be sampled by the device of thisinvention may include cement, talc, flour and finely divided ore andsimilar granular materials. However an especially desirable applicationof the sampler is with continuously flowing streams of TiO materialssuch as for example, the discharge of Ti0 from a Raymond mill cyclone;or the TiO burdened reaction gases produced in a vapor phase process forproducing pyrogenic TiO To illustrate the invention further theparticular embodiment thereof above described was used to take samplesperiodically from a stream of TiO pigmentary material in the dischargeduct of a Raymond mill. The jet orifice 14 comprises a A hole drilled ina plug welded in the end of a /s" tubular member 11. The samplecollector comprised a three inch 45 elbow diametrically opposite the jetorifice 14. Filtered air was supplied to the solenoid operated valve 18which in this embodiment was a 2-way valve, normally closed, andprovided with a /s" orifice. A Mi" pipe connected the solenoid operatedvalve 18 to a coupling 15. A variable timer 19 was selected which wasset for a five minute period and a duration of /2 second such that thesolenoid 18 was operated every five minutes for /2 second to allow airto issue from the jet orifice 14. Approximately 0.005 cubic feet of airpassed through the orifice in /2 secondwhich imparted suificientmomentum to the TiO pigment particles to carry them across the conduitinto the sample collector 20. Samples of TiO pigment from the dischargeduct of a Raymond mill were uniformly +325 mesh with no indication ofclassification or foreign matter.

While one embodiment of the invention has been shown and described itwill be apparent that other adaptations and modifications may be madewithout departing from the scope of this invention.

I claim:

1. A pneumatic device for obtaining a sample of pulverulent materialcomprising in combination: a conduit through which said pulverulentmaterial is adapted to flow in a continuous stream, a tubular memberconstructed and arranged in one wall of said conduit, gas supply meansarranged to deliver a high velocity gas to said tubular member, samplecollecting means constructed and arranged substantially diametricallyopposite said tubular member, and valve means constructed and arrangedto control the emission of said high velocity gas from said supply meansto said tubular member so as to produce a blast of gas from said tubularmember, said blast of gas serving to carry a sample of thepulverulentmaterial out of said stream into said sample collectingmeans.

2. A pneumatic device for obtaining a sample of pulverulent materialaccording to claim 1 wherein said tubular member comprises a jetorifice.

3. A pneumatic device for obtaining a sample of pulverulent materialaccording to claim 1 wherein said sample collecting means comprises atubular elbow having an entrance end constructed and arranged to extendinto said conduit and to be shielded from the stream of material flowingthere through.

4. A pneumatic device for obtaining a sample of pulverulent materialaccording to claim 1 wherein said gas supply means comprises a pipe lineconnected to a pressurized gas source; and said valve means comprises asolenoid operated valve in said pipe line, and a timer for periodicallyenergizing said solenoid.

5. A pneumatic device for obtaining a sample of pulverulent materialaccording to claim 4 wherein said gas supply means comprises a gaschamber arranged to be connected to said valve-means, said gas chamberhaving a restricter connected to said pressurized gas source.

6. A pneumatic device for obtaining a sample of pulverulent materialaccording to claim 3 wherein said tubular elbow has an exit end arrangedto extend outside said conduit; and a sample receiving receptacleassociated with the exit end of said tubular elbow.

7. A pneumatic device for obtaining a sample of pulverulent materialaccording to claim 6 wherein a gasket is constructed and arranged toprovide a dust tight seal between the exit end of said tubular elbow andsaid sample receiving receptacle.

8. A method for removing a sample from a continuously flowing stream ofpulverulent material comprising: passing said stream of pulverulentmaterial between a gas jet orifice and an oppositely disposed samplecollector, and periodically emitting a blast of gas from said jetorifice into said stream substantially in alignment with said oppositelydisposed sample collector to carry a sample of said pulverulent materialfrom said stream into said Sam ple collector.

9. A method for removing a sample from a continuously flowing streamaccording to claim 8 wherein the frequency and duration of said gasblast are variable.

10. A method for removing a sample from a continuously flowing stream ofpulverulent material according to claim 8 wherein said pulverulentmaterial is pigmentary TiO References Cited UNITED STATES PATENTS782,235 2/1905 Gullberg 73-423 1,840,455 10/1927 Lea 73-423 3,016,0637/1960 Hausmann 302-42 3,250,128 5/1966 Cassel 73-422 LOUIS R. PRINCE,Primary Examiner.

H. C. POST, llLAssistant Examiner.

